Evidence of Ancient Lake on Mars

Researchers at the University of Colorado at Boulder have discovered evidence of shorelines on Mars, indicating the presence of an ancient lake on the Red Planet. Found on a broad delta with a series of alternating ridges and troughs, the shoreline indicates the lake was approximately the same size as Lake Champlain (around 80 square miles around and up to 1500 feet deep).

Scientists believe the ridges and troughs they discovered are the surviving remnants of beach deposits from the lake. A project lead by Research Associate Gaetano Di Achille with the help of Assistant Professor Brian Hynek and Research Associate Mindi Searls all of the University of Colorado at Boulder Laboratory for Atmospheric and Space Physics, discovered the shoreline while examining images taken by the High Resolution Imaging Science Experiment (HiRISE) on NASA’s Mars Reconnaissance Orbiter. HiRISE orbits about 200 miles above the planet but can resolve features as small as one meter in size on the surface.

Located in a large valley called the Shalbatana Vallis, the remnants of the lake deposited sediment that formed the delta observed in the photographs. The images also indicate that water carved a 30 mile long canyon opening into the valley. The observed geological features indicate a stable, long-lived lake in that location. The lack of additional shorelines indicates the lake likely dried up very quickly, possibly during a period of rapid climate change.

Interestingly, the lake has been placed in an era about 300 million years after the wet and warm Noachan epoch when the planet was bombarded by meteors and experienced extensive flooding. Instead, it formed during the Hesperian epoch, typically characterized by lava flows and the formation of volcanoes like Olympus Mons.

Scientists are particularly interested in exploring the deltas near the lake. On Earth such deltas are rich with organic carbon and other biomarkers. If a Mars with water and life was similar, these deltas represent a good opportunity to find signs of life on the planet. These deltas would be a prime landing target for a future Mars mission capable of soil analysis and other types of physical examination of the area. Researchers believe such a mission could lead to proof that life existed on Mars in the past.

Janice Karin has a B.A in physics from the University of Chicago and a
M.S. in physics from the University of Pennsylvania. In addition to
extensive experience as a technical writer focused on development
tools, databases, and APIs, Janice has worked as a freelance reporter,
editor, and reviewer with contributions to a variety of technology
websites. One of her primary focuses has been on PDAs and mobile
devices, but she is interested in many other areas of science and
technology.